TiO 2 photocatalyst film using circulating fluidised bed–chemical vapour deposition

Abstract

TiO₂ photocatalyst beads were synthesised using the circulating fluidised bed–chemical vapour deposition (CFB-CVD) method. Their photocatalytic activity was compared with the TiO₂ photocatalyst balls synthesised using the conventional CVD (C-CVD) method. The TiO₂ film synthesized by CFB-CVD showed (110) oriented anatase crystal structure. Compared to the film synthesised by C-CVD, the CFB-CVD synthesised film had much less dense crystal structure owing to TiO₂ powders precipitated during the film growth. When the CFB-CVD synthesised TiO₂ beads were used in the photocatalytic decomposition of RhB in a fluidised bed reactor, the decomposition rate increased with increasing UV intensity and circulating flowrate and with decreasing initial RhB concentration. One important shortcoming of the TiO₂ photocatalyst beads synthesised by CFB-CVD turned out to be that the photocatalytic activity was decreased significantly by repeated reuse, calling for further investigation to improve the durability.